离散化.区间和acwing.802

#include<bits/stdc++.h>
using namespace std;
const int N = 200000;
int a[N],b[N],c[N],s[N];
int n,m;
int main()
{
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;++i)
    {
        scanf("%d%d",&a[i],&b[i]);
        c[i]=a[i];
    }
    sort(c+1,c+n+1);
    int cnt=unique(c+1,c+n+1)-c-1;
    for(int i=1;i<=n;i++)
        a[i]=lower_bound(c+1,c+cnt+1,a[i])-c,s[a[i]]+=b[i];
    for(int i=1;i<=cnt+1;i++)s[i]+=s[i-1];
    for(int i=1;i<=m;i++)
    {
        int x,y;
        scanf("%d%d",&x,&y);
        int dx=lower_bound(c+1,c+cnt+1,x)-c;
        int dy=lower_bound(c+1,c+cnt+1,y)-c;
        if(c[dy]>y)dy--;
        if(dy<dx)puts("0");
        else printf("%d\n",s[dy]-s[dx-1]);
    } 
    return 0;
}